Multiple Input Multiple Output (MIMO) wireless communication transmission schemes allow for greater data throughput on a single wireless channel. This greater throughput is accomplished using the multipath characteristics inherent in the transmission of wireless signals. These characteristics stem from the fact that a wireless signal transmitted from a single antenna element may bounce off of various objects before being received at a receiver antenna element. The receiver antenna element thereby receives what is essentially the same signal multiple times as the signals that have bounced off the various objects arrive at the antenna element. The receiver antenna element is able to process the received multipath signals to obtain the signal that was originally transmitted.
MIMO transmission schemes take advantage of this fact that a receiver can distinguish an originally transmitted signal from multipath signals in order to increase data throughput. To do this, MIMO schemes use multiple antenna elements to transmit communications over the same channel. Using multiple antenna elements allows a MIMO scheme to divide a communication signal into components for transmission over the multiple antenna elements rather than transmitting the communications over a single element. This effectively multiplies the throughput of the wireless channel by the number of antenna elements. When a MIMO receiver receives communications from each MIMO transmission antenna element, the MIMO receiver is able to distinguish the communications from each element in order to recompile the original communications that were split for MIMO transmission.
While many modern wireless communication devices, such as cellular phones, are capable of receiving MIMO communications, the devices are unable to transmit MIMO signals because the devices lack the multiple antenna elements necessary for transmitting MIMO communications. Specifically, the size and packaging requirements of the devices prevent the devices from having the necessary space for the placement of the multiple antenna elements. Therefore, many wireless devices on their own can receive but not transmit MIMO communications.
Overview
Embodiments disclosed herein provide systems and methods for improving reverse link throughput using Multiple Input Multiple Output (MIMO) across multiple wireless devices. In a particular embodiment, a method provides, in a first wireless communication device, receiving a user instruction to execute an application associated with a wireless protocol over a MIMO transmit antenna system, wherein the wireless protocol separates users on a wireless channel using Walsh codes. In response the user instruction, the method provides transferring a wireless probe signal to identify whether an external MIMO antenna element is available over another wireless protocol that does not interfere with the wireless protocol and receiving a wireless response signal indicating an availability of the external MIMO antenna element over the other wireless protocol. The method further provides generating a signal with a Walsh code for the application and wirelessly transmitting at least a first portion of the signal with the Walsh code from an internal MIMO antenna element for receipt by a MIMO receive antenna system. The method further provides wirelessly transmitting at least a second portion of the signal with the Walsh code over the other wireless protocol, wherein a second wireless communication device including the external MIMO antenna element receives at least the second portion of the signal with the Walsh code over the other wireless protocol and wirelessly transmits at least the second portion of the signal with the Walsh code from the external MIMO antenna element for receipt by the MIMO receive antenna system.